Laundry apparatus



Dec. 139 w66 J. A, scm/VIN@ ETAL 3,299,909

LAUNDRY APPARATUS Filed Oct. '7, 1964 2 Slxeets$heet l /f /Gx /3 D 13,1966 A. scHwlNG ETAL. 3,290,909

LAUNDRY APPARATUS MAX/MUM United States Patent Oilce 3,299,999 PatentedDec. 13, 1966 3,290,909 LAUNDRY APPARATUS Joseph A. Schwing, llenndel,Pa., and Ivan ll. Danylenko,

This invention relates to laundry apparatus, and more particularly towashing machines of the type comprising a rotatable wash basket mountedwithin a resiliently suspended tub.

In washing machines of the foregoing type the drain opening for the tubis usually placed in a lower region of the tub and a pump is provided ata level below the tub to pump the water therefrom as the basket isrotated at a speed su'icient to centrifuge water from the clothing.Under conditions of excessive unbalance, due to uneven distribution ofclothes in the basket, the resiliently mounted tub will move orbitally,and as a result water chasing occurs and exposes the drain opening tothe ambient atmosphere. Such occurrence introduces air into the pump viathe drain opening, causing the pum-p to become air locked. Once the pumpis air locked little or no water is pumped from the tub. This conditionresults in reduction in centrifuging speed, due to the braking action ofthe water between the basket and the tub, with consequent excessiveretention of water by the clothes.

It is a primary objective of this invention to provide simple andeffective means for preventing air locking of -a washing machine drainpump.

The invention is featured by the provision of simple and effective meansfor venting air from the liquid drain pump of a washing machine withoutdetracting substantially from the eiliciency of the pump.

In achievement of the foregoing and other objectives the inventioncomprises a washing machine tub adapted `to contain liquid and a drainpump for the tub disposed at a level below the minimum liquid level inthe tub. The pump includes an impeller housing provided with an inletport connected to a drain sump portion of the tub below the said minimumliquid level and an outlet port adapted for connection to a liquiddisposal drain above the `maximum liquid level in the tub. Means isprovided for preventing air locking of the pump, including `an air bleedport for an upper portion of said housing, and open ended conduit meansextending from the air bleed port and having its open end disposed forair flow communication with the ambient atmosphere, during operation ofthe ptunp, at a level substantially above the level of the inlet port ofthe pump housing.

It is a feature of the invention that the air bleed port and conduitmeans associated therewith will vent air from the pump in the event airis introduced into the pump as a result of premature uncovering of thetubs drain sump portion in the final stages of clothes centriinging.

For a more complete understanding of the invention, reference may bemade to the following description taken in light of the accompanyingdrawing, in which:

FIGURE 1 is a perspective showing of a washing machine of atype to whichthe invention is particularly applicable;

FIGURE 2 is an elevational showing, partly in section and with partsbroken away, of a preferred embodiment of a fluid handling circuit incombination with the machine illustrated in FIGURE 1;

FIGURE 3 is a showing similar to FIGURE 2 and illustrating a modiedembodiment of the invention; and

FIGURE 4 is a chart illustrative of certain performance characteristicsof a machine utilizing the invention, and comparing such characteristicswith a prior art machine.

With more detailed reference to the drawing, and first to FiGURES l `and2, the illustrated washing machine 1l? comprises a cabinet 11 having acontrol panel 12 and an upper wall 13 provided with `an aperture 14 overwhich a hinged door 15 is disposed. A rotatably mounted basket 16,provided with perforations 20, is nested within the tub 17 and each hasan upwardly presented opening `aligned with aperture 14 in wall 13. Anagitator 21 is mounted for movements relative to basket 16 to providefor washing and rinsing fabrics in the basket. Agitator 21 is preferablyof the wobble-type and is driven by known means including a shaft 22, apulley 23, a reversible motor 2d, a motor pulley 25, and a belt 26 thatdrivingly interconnects the pulleys. Tub 17 and basket 1d 4are supportedupon a column 1S resiliently mounted in its lower region upon ahorizontal part of base portion 19 of cabinet 11.

Motor 2d is of known reversible type, and when rorated in one directiondrives shaft 22 to operate agitator 21, while activating brake means(not shown) to lock spin tube 38 and prevent rotation of the basketaihxed thereto. When the motor is rotated in the other direction thebrake means is deactivated to release spin tube 38 and permit rotationof the agitator and basket as a unit, to centrifuge wash liquid fromclothes within the basket through the perforations 20 in the latter.Structural details of a machine of the foregoing type, are disclosed andclaimed in U.S. Patent No. 3,102,408 granted to Joseph Pelensky and inthe copending application of the same inventor, Serial No. 161,962, nowU.S. Patent No. 2,243,021 issued March 29, 1966, filed December 26,1962. Both are assigned to the assigneeI of the present invention.

With further reference to FIGURE 2, a wash liquid drain pump 27 isdisposed atop motor 24 and below tub 17. Pump 27 includes an impeller28, driven by the upper end of the motor'shaft to which pulley 25 isattached, and an impeller housing 29 having a pair of ports, one portbeing disposed in fluid flow communication with a flexible conduit orhose 31 attached to a liquid drain sump portion 32 of tub 17. The otherport of housing 29 is connected to a liquid discharge conduit or hose 30that terminates at a level above the maximum liquid level in the tub.Hose 30 is adapted to direct discharged liquid into `suitable drainmeans (not shown) having its inlet disposed at a level also above themaximum liquid level in the tub.

In particular accordance with the invention, and still Awith referenceto FIGURE 2, an air bleed port 33 is provided in the upper, generallydome-shaped portion of impeller housing 29. An open ended conduit 34extends upwardly from port 33 and has its open end 35 disposed for airflow communication with the ambient atmosphere at a level substantiallyabove the level of the inlet port of the pump, in this case the openingbeing substantially at the level of the top of tube 17. Open end 3Scomprises an air flow restrictive orifice, for example an `orifice about.O31 inch in diameter, conveniently formed in a plug fitted withinconduit 34.

Rotation of motor 24 in the direction to operate agita. tor 21 duringeither a washing or a rinsing phase, when the tube is filled with liquid(prior to a centrifuging or spin phase for removing the liquid) causesthe pump impeller 28 to be rotated in a direction in which the portconnected to `drain hose 31 is the discharge port and the port connectedto the discharge hose 30 is the inlet port. Under this condition thepump maintains a head sufficient to prevent outflow of liquid from tub17 through drain sump hose 31. A relatively small amount of air is drawnin through discharge hose 311 and forced through conduit 31 into thebottom of tub 17. There is little or no pumpinduced flow of air intoopen end 35 of the bleed conduit 34, due to the restrictive size of theorifice and the relatively small pumping effect obtainable in the regionof bleed port 33. It is desirable to keep this air flow at a minimum toprevent so-called dotation of the clothes which interferes withagitation.

Following either the wash or the rinse phase, motor 24 is reversed torotate basket 16 at its clothes centrifuging speed, and to rotate pump27 in a direction to drain fluid from tub 17 through conduit 31 fordischarge through hose 30. As the liquid level is lowered, the basketsrotational speed increases. Assuming a condition of clothes unbalance inthe rapidly spinning basket, the entire tub basket, and resilientlymounted support column 18 will nutate about its support upon baseportion 19. This motion results in a large mass of water chasing thespinning basket, thereby augmenting the clothes unbalance. This body ofwater extends between the basket and the tub and exerts a braking forceon the 'basket to reduce its speed. Also this body of water alternatelycovers and uncovers the drain sump, air-locking the pump at the initialuncovering. This condition renders the pump inetfective to remove theremaining wash liquid, leaving the clothes in an excessively dampcondition which is particularly disadvantageous following the final spinphase when relatively low retention of water is desired.

In the apparatus of the present invention, each time the water coversthe opening in the drain sump, following each uncoveringf the statichead of the water will cause it to ow downwardly from sump 32 throughdrain hose 31 and into pump 27, while air is forced in advance of theWater and vented to the atmosphere through vent hose 34 and the orificein open end 35. By virtue of this construction, the pump is primed foreach covering of the drain sump by the wash liquid, and a pulsating fiowof liquid continues until the tub is emptied. Progressive removal of theliquid reduces the braking action, and permits increase rotational speedof the basket effective substantially to spin-dry the clothes.

With reference to FIGURE 3, a modified embodiment of the invention isillustrated in a machine of the type shown in FIGURE 2 and comprisingthe same essential elements, such as -agitator 121, motor 124, basket116 provided with perforations 1211, and tub 117 supported upon column118. A rotary impeller pump 127 is disposed atop motor 124 and includesa housing 129 and an impeller 128. An air bleed port 133 is provided inhousing 129 and is in `air flow communication with a vent hosecomprising an upwardly extending portion 134 and a downwardly extendingportion 136. The upwardly extending portion 134 is connected to theupper region Of an enlarged vessel comprising a surge tank 137 disposedsubstantially at the level of the tub opening, and the `downwardlyextending portion 136 is `connected to the bottom region of the surgetank. The downwardly extending portion of the vent terminates in a fluidflow connection 135 leading through the side wall of tub 117 and ventingtherein.

In operation of the apparatus shown in FIGURE 3, rotation of motor 124in the direction to rotate shaft 122 and operate agitator 121 will alsorotate impeller 128 in a direction balancing the head of liquid in thetub 117 and drain hose 131 to prevent outliow of wash liquid, as was thecase in the FIGURE 2 embodiment of the invention. Also during thisoperation, for which the wash liquid is at or near the maximum level asindicated, liquid will fill the tub drain conduit 131, pump housing 129,and a portion of the vertically extending portion 134 (see broken line)of the air bleed conduit. Also, liquid will rise only part way into thedownwardly extending portion 136 (see broken line) of the air bleedconduit, there being air trapped in the surge tank 137. The presence ofair in the upper portion of this inverted U-tube arrangement prei ventsliquid in the tub from being recirculated to interferc with agitatorinduced liquid flow, and the connections to the tank 137 are such as toensure provision of an air lock in this arrangement despite any suddenpressure surges that may occur. For example, While the tub is fillingwith liquid, the motor and pump are inoperative. When the tub has filledto the maximum level, or such other operating level as may have beenselected, the rnotor is started to operate the agitator. Starting of themotor also starts the pump, which action is accompanied by a relatvielyshort-term, low-pressure surge at the eye of the pump, in the region ofbleed port 133. However, due to the relatively large volume of tank 137,any short term liquid flow upwardly through conduit portion 136, due tothe low pressure surge at the pump, is dissipated in the surge tank.

Upon initiation of the spin phase, by reversing the motor 124 to rotateboth shaft 122 and spin tube 138 following either a wash or a rinsephase, liquid is forced through port and upwardly through conduitportion 136, due to centrifugal force created by the rapidly rotatingbasket 116. The entrapped air in the inverted U- tube means is driven bythe Water through tank 137 and conduit portion 134, into pump housing129 by way of air bleed port 133. This liquid joins the liquid withdrawnthrough drain hose 131, and the joined streams of liquid are pumped outthrough the discharge hose 130. This dual intake enhances the dischargeflow rate in its initial stages, thereby to ensure removal of washliquid in the time allotted to the spin phase. This is important whenthe liquid level of the tub is sufficiently lowered, connection 135 ofconduit portion 136 breaks to air, and the pumping rate of pump 127 issomewhat reduced. Upon breaking of the liquid seal to port 135, thesurge tank 137 and its associated conduits provide an air vent path forany air introduced into pump housing 129 due to water chasing, as wasdescribed in connection With the previous embodiment illustrated inFIGURE l.

Advantages deriving from the present invention are demonstratedgraphically in FIGURE 4. In tests conducted by applicants assignee, aprior art machine (A- non-vented) was operated under a controlledunbalance condition in its linal spin phase. Residual liquid in the tub,which had not been removed due to air locking of the pump, amounted tol5 pounds. In contrast, similar tests on the FIGURE 2 embodiment (C)resulted in an average of 2% lbs. of residual liquid, and tests on theFIGURE 3 embodiment (B) resulted in an average of 2l/2 lbs. of residualliquid.

In summary, the invention provides simple and effective means forpreventing air locking of a washing machine drain pump, withoutdetracting substantially from the efficiency of the pump.

We claim:

1. In a Washing machine including a tub adapted to contain liquid, and adrain pump for said tub disposed at a level below the minimum liquidlevel in said tub, said pump including an impeller and a housing for thelatter provided with an inlet port connected to a portion of said tubdisposed below said minimum level and an outlet port adapted forconnection to a drain disposed above the maximum liquid level in saidtub, means for preventing air locking of said pump, comprising: an airbleed port for an upper portion of said housing; and open ended conduitmeans extending from said air bleed port and having its open enddisposed for air flow communication with the ambient atmosphere, duringoperation of said pump, at a level substantially above the level of saidinlet port of said pump housing, said conduit means including oneportion that extends upwardly to a region adjacent the upper portion ofsaid tub, and another portion that extends downwardly and has its openend communicating with said tub through a lateral wall portion thereof.

2. A machine according to claim 1 and further characterized in that saidconduit means includes an enlarged section between the recited upwardlyand downwardly extending portions, the downwardly 'extending portioncommunicating with the lower region of said enlarged section and theupwardly extending portion communicating with the upper region of saidenlarged section.

3. A washing machine including a tub adapted to contain liquid, a basketfor clothes rotatably mounted within said tub to centrifuge wash liquidfrom clothes contained therein into said tub, a drain sump in the lowerportion of said tub, for draining liquid from said tub, said liquid bengsusceptible of chasing whereby said drain pump is uncovered and exposedto the atmosphere, a drain pump for said tub disposed at a level belowsaid sump, said pump including an impeller and a housing for the latterprovided with an inlet port connected to said tub sump and an outletport adapted for connection to a drain at a level above the maximumliquid level in said tub, and means for preventing air locking of saidpump upon exposure of said sump to atmosphere comprising an air bleedport for an upper portion of said housing and open ended conduit meansextending from said air bleed port and having its open end disposed forair flow communication with the atmosphere, during operation of saidpump, at a level substantially above the level of said inlet port ofsaid pump housing, said conduit means including one portion that extendsupwardly to a region adjacent the upper portion of said tub, and anotherportion that extends downwardly and has its open end communicating withsaid tub through a lateral wall portion thereof.

4. A machine according to claim 3 and further characterized in that saidconduit means includes an enlarged section between the recited upwardlyand downwardly extending portions, the downwardly extending portioncommunicating with the lower region of said enlarged section and theupwardly extending portion communicating with the upper region of saidenlarged section.

5. A washing machine including a tub adapted to con tain liquid, abasket for clothes rotatably mounted within said tub to centrifuge washliquid from clothes contained therein into said tub, clothes and washliquid agitator means within said basket operable while said basket isheld substantially stationary, reversible drive means rotatable in onedirection to rotate said basket and said agitator means as a unit, saiddrive means being rotatable in the other direction to drive saidagitator means while said basket is held stationary, a drain sump in thelower portion of said tub for draining liquid from said tub, said liquidbeing susceptible of chasing as said basket is rotated at centrifugingspeeds, whereby said drain sump is uncovered and exposed to theatmosphere, a drain pump driven by said reversible drive means for saidtub disposed at a level below said sump, said pump including an impellerand a housing for the latter provided with an inlet port connected tosaid tub sump and an outlet port adapted for connection to a drain at alevel above the maximum liquid level in said tub, and means forpreventing air locking of said pump upon exposure of said sump toatmosphere when the drive means is driven in a direction to rotate saidbasket at centrifuging speed, comprising: an air bleed port for an upperportion of said housing; open ended conduit means extending from saidair bleed port and having its open end disposed for air flowcommunication with the atmosphere, during operation of said pump, at alevel substantially above the level of said inlet port of said pumphousing; and means for impeding the ow of air through said conduit meansinto said pump as it is driven with the drive means while the latterrotates in the direction for driving the agitator means, said means forimpeding air flow being associated with said conduit means in a regionabove the level of liquid in said tub, and permitting outflow of airfrom said pump as it tends to become air locked when said basket isrotated at centrifuging speed.

6. A washing machine according to claim 5, and characterized in thatsaid means for impeding air ow comprises an air Flow restrictive orificedisposed in series air iiow relation with the recited open end ot saidopen ended conduit means.

7. A washing machine according to claim 5 and characterized in that saidconduit means includes one portion that extends upwardly to a regionadjacent the upper portion of said tub, and another portion that extendsdownwardly and has its open end communicating with said tub through alateral wall portion thereof, and said means for impeding the ow of aircomprises an en larged section between the upwardly and downwardlyextending portions of said conduit means, the downwardly extendingportion communicating with the lower region of said enlarged section andthe upwardly extending portion communicating with the upper region ofsaid enlarged section.

References Cited by the Examiner UNITED STATES PATENTS 2,901,294 8/1959Smith 68--23 X 3,018,650 l/l962 Schmidt 68-208 X FOREIGN PATENTS1,290,705 3/1962 France.

WILLIAM I. PRICE, Primary Examinez'.

1. IN A WASHING MACHINE INCLUDING A TUB ADAPTED TO CONTAIN LIQUID, AND ADRAIN PUMP FOR SAID TUB DISPOSED AT A LEVEL BELOW THE MINIMUM LIQUIDLEVEL IN SAID TUB, SAID PUMP INCLUDING AN IMPELLER AND A HOUSING FOR THELATTER PROVIDED WITH AN INLET PORT CONNECTED TO A PORTION OF SAID TUBDISPOSED BELOW SAID MINIMUM LEVEL AND AN OUTLET PORT ADAPTED FORCONNECTION TO A DRAIN DISPOSED ABOVE THE MAXIMUM LIQUID LEVEL IN SAIDTUB, MEANS FOR PREVENTING AIR LOCKING OF SAID PUMP, COMPRISING: AN AIRBLEED PORT FOR AN UPPER PORTION OF SAID HOUSING; AND OPEN ENDED CONDUITMEANS EXTENDING FROM SAID AIR BLEED PORT AND HAVING ITS OPEN ENDDISPOSED FOR AIR FLOW COMMUNICATION WITH THE AMBIENT ATMOSPHERE, DURINGOPERATION OF SAID PUMP, AT A LEVEL SUBSTANTIALLY ABOVE THE LEVEL OF SAIDINLET PORT OF SAID PUMP HOUSING, SAID CONDUIT MEANS INCLUDING ONEPORTION THAT EXTENDS UPWARDLY TO A REGION ADJACENT THE UPPER PORTION OFSAID TUB, AND ANOTHER PORTION THAT EXTENS DOWNWARDLY AND HAS ITS OPENEND COMMUNICATING WITH SAID TUB THROUGH A LATERAL WALL PORTION THEREOF.